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Archive for the ‘Django’ Category

Debates about which programming language is the best are always hard and heated. Likewise, there’s no ideal language that works for all web application project requirements. Wikipedia is written in PHP. Gmail is written in Java. Python is number one choice of Google and YouTube. Ruby is used to create Twitter and Hulu. Slashdot is written in Perl. Stackoverflow is written in C#.

Browsing for the best web programming languages, among dynamic ones, you’ll mostly see PHP, Python and Ruby listed. Back in the days several years ago PHP was admitted the best tool for web job but since then both Python and Ruby have matured and grown robust libraries and frameworks around them that make them better candidates for many web projects now.

Today many consider PHP to be great for average everyday web systems. Python and Ruby are thought to be more suitable than PHP for most web applications in general and for more advanced things in particular. Just like PHP, they are free, open source, run on an open source stack (Apache and Nginx / linux, windows and BSD), and play well with any database engine. However, Ruby and Python have better syntax and they both enforce good programming habits by their nature, especially Python. PHP encourages sloppy spaghetti code by its nature. Also, the object oriented features in PHP are very ugly because of its arcane, retarded syntax.

Let’s get deeper insights into these two web programming languages from various standpoints:

As mentioned before, Python and Ruby are two of the most popular dynamic programming languages used in high level application development. In fact, Ruby was built using some of the design elements from Python. Developers often prototype using these two languages before implementing on compiled languages because of their modularity and object oriented features. Many use Python or Ruby instead of Perl as simple scripting languages. Python and Ruby are popular among web developers as well because of their rapid development cycle, with Python boasting computation efficiencies and Ruby boasting code design.

a/ Philosophy
Python really believes that code readability is the most important thing. Hence, there is one-true way of writing code, or as it has been reformulated lately: “There’s a most understandable way to do something and that is how it should be done”. Python is designed to strongly emphasize programmer productivity and it likes things to be structured, consistent, and simple. Python syntax enforces strict indentation rules; in fact, indentation has semantic meaning in Python.
Ruby believes in giving programmer the flexibility, freedom and power. It was designed, first and foremost, to make programming fun for its creator, with guiding concepts as follow: “The Principle of Least Surprise” and “There’s more than one way to do the same thing”. The latter philosophy principle inherited from Perl is the reason why many Ruby methods have alternate names, which may lead to some API confusion among new practitioners. However, this flexibility enables Ruby to be used as a meta language for describing DSL. Also Ruby provides a better way to write concise and compact code. More into the expressiveness of the code and writing code that is clever.
Python people like libraries to be transparent and obvious how they work and hence is easier to learn, while Ruby people tend to provide clean and pretty interfaces with “magic” behind the scenes. This makes development very fast when you understand the magic, but frustrating when you don’t.

b/ Ease of Use
Python is known for its ease of use. It allows beginners to start building powerful sites more quickly, and has the power to grow in complexity keeping its ease of comprehension. For example, one of the hardest parts of coding is going back to what you coded long ago and trying to remember the logic of it. Because Python uses natural language with white spaces and indenting, it is much more clear and easier to read than languages like Ruby. That makes it easier to fix mistakes or do updates. Also, there are literally thousands of pre-built modules that can be snapped on to let you get up and running on the web immediately. Its intuitive introduction to object-oriented coding concepts, such as communities, modules, and libraries, allows you to move on to other related programming languages as they develop.

c/ Object Oriented Programming
Both Python and Ruby support object oriented programming. Still Ruby’s object orientation is considered to be more ‘pure’ in that all functions exist inside a class of some sort. Python’s object orientation is more akin to that of C++, which allows functions and statements that exist outside of classes. In Ruby, even global variables are actually embedded within the ObjectSpace object. Python doesn’t have global variables, instead using attributes of module objects. In Python and Ruby, an instance of literally any type is an object. However, where in Ruby all functions and most operators are in fact methods of an object, in Python functions are first-class objects themselves.

d/ Syntax
Ruby includes several syntactic features which make dynamic extension of and higher-order interaction with external (library) code more straightforward. In particular these are blocks and mix-ins. Most things implementable with block and mix-in syntax are also achievable in Python, they are simply less syntactically natural and clear, and so less commonly form the centerpiece of major libraries or common styles of programming. These features, combined with a lighter-weight syntax with fewer restrictions (whitespace flexibility, optional parentheses, etc), make Ruby more suitable to pervasive and relatively transparent use of metaprogramming.
At the same time, while this flexibility and the Ruby community’s tendency to use it for metaprogramming can facilitate aesthetically pleasing code, they can also create stylistic variation in how the language is used, and obscure the mechanisms by which code actually works. Python’s more restrictive syntax is intentionally designed to steer developers towards one canonical “pythonic” style to improve accessibility and comprehension.

e/ Style
Ruby code is organized into blocks, with blocks starting with various constructs and ending with the keyword “end”. Python code is indentation-sensitive, with successively larger indentation meaning tighter (nested) scopes. Python’s syntax has been described as executable pseudocode.

f/ Functional Programming
Both languages support some functional programming constructs, but Ruby is arguably better suited to a functional programming style. Lambdas in Python are generally very short, because lambdas in Python are restricted to expressions and cannot contain statements. Ruby’s lambda support is far more flexible, allowing for lambda expressions of arbitrary length.

g/ Speed
The standard CPython implementation is generally regarded as executing code slightly faster than Ruby.If speed is really an issue for a Python project, you also have the option to use Cython, Pyrex,Pypy (JIT) or the ShedSkin tools to compile your code into C or C++.

j/ Features
Both Python and Ruby are high level application development languages. Each of them is estimated to have a Capers Jones language level of at least 15. Both languages promote test driven development.
Both languages have full Unicode support, although the way that support is implemented varies. Python distinguishes between “Unicode strings” and “byte-strings”. Ruby, on the other hand, treats all strings as byte-strings with a semi-hidden flag which causes problems when dealing with badly-encoded data from third-party sources.
Both Python and Ruby support multithreading. Python has the Global Interpreter Lock (GIL), which negates much of the potential advantage of using threads; Ruby has a comparable Global VM Lock (GVL).
There are a number of functions that are available by default in Ruby but for which in Python it is necessary to import a module from the standard library. Python supports generators and generator expressions.

k/ Community
There are great communities behind both frameworks. Some people believe that Python has a more developed community in terms of libraries suited for data analysis, machine learning, natural language processing, scientific libraries. As for community folks, Python ones are believed to be conservative and afraid of change, while Ruby guys welcome changes and love new shiny stuff even if it breaks older things. Consequently, Python world is more stable, and you can update your installation without much troubles, but that also means new technology is only added very slowly.

l/ Frameworks
There are a number of Web frameworks based on both Ruby and Python. The most notable and leading are Ruby on Rails (Ruby) and Django (Python) based on MVC. Django is more declarative, with it you’ll have a clearer understanding of what’s actually going on. It lets you specify most configuration details yourself. Django creates a much simpler project structure. On the other hand, the centerpiece of Rails’s philosophy is called convention over configuration. Rails provides you with more defaults.

m/ Popularity
Python is generally more widely used than Ruby, according to most measures, but in the wake of the rising popularity of the Ruby on Rails Web application development framework Ruby’s popularity too has seen rapid growth.
Python is more mature general purpose nature vs Ruby’s more niche (Rails) usage. Python is stronger and sees use in automating system administration and software development, web application development, data manipulation, analyzing scientific data (with help of numpy, scipy, and matplotlib modules), biostatistics, and teaching introductory computer science and programming. Ruby+Rails holds a slight edge over Python+Django for web development and sees use in general programming, and has more mindshare.
In terms of cloud deployment, Python can run on Google-Cloud (Google-App engine). Though Ruby has very strong cloud deployment options in the shape of Heroku and Engine Yard.

Would you prefer Python or Ruby over PHP for implementation of your web project? And is it indeed a philosophy that you chose while selecting between Python and Ruby? Interested to hear your thoughts.

Helen Boyarchuk

Helen Boyarchuk
Helen.Boyarchuk@altabel.com
Skype ID: helen_boyarchuk
Business Development Manager (LI page)
Altabel Group – Professional Software Development

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It’s surprising that in our blog we have never written about Python frameworks and Python itself either. So, I’ve decided to help out the omission :)

When choosing a framework for site development you have many things to consider. If the criterion is a programming language, for Microsoft and C# followers the choice is clear – ASP.NET. Those who are in love with Ruby don’t have to think too much either – Ruby on Rails will be their choice. It’s much more complicated for Python, PHP and Java developers to make up their mind: the quantity of frameworks here is tremendous.

Firstly, I want to underline the pluses of Python frameworks in general:

  • Usage of Python language. I’m sure lots of programmers are pretty tired of praising Python. But to write a site on Python is really faster, cheaper and more pleasantly than on  other languages.
  • Wide choice. Frameworks abundance can be scaring only for beginners. A professional always welcomes the freedom of choice, as the chance to find what you really need only increases. Besides, choice entails competition, and healthy competition leads to quality improvement of every framework.
  • Rapid development. New frameworks emerge constantly, and their precursors either give their way to the younger ones, or continue their struggle for leadership: bugs are fixed, new features are implemented. It differentiates Python community from, Ruby community, for instance, which is represented mostly by Ruby on Rails. Due to the lack of new ideas we can see some standstill in Ruby on Rails development.
  • Opensource. They say using quality software on a legal and free basis is really cool :)

For now there are several dozens of Python frameworks. Among them are famous Django, Pylons, Turbogear, and some other interesting ones, as Zope, Twisted, CherryPy.

Today I want to make a short review of the more popular Python framework – Django.

Django was created specially for convenient news site development of The World Company. It had been developed since 2000, but to the general public it was presented only in the middle of 2005. The framework got its name after a Belgian jazz guitarist and composer Django Reinhardt.

Django site is built from one or several applications, which are recommended to be made alienable and interconnected (unlike Ruby on Rails, for example). One of the main Django advantage is excellent documentation, and, I suppose, the biggest community among all the Python frameworks.

When getting acquainted with Django, firstly, his built-in administrator interface wins over. It provides convenient work with the content of a written site. You should change the settings a little bit, then following the link http://127.0.0.1:8000/admin you can start the page through which it is easy to manage the content (for example, to look through the data base content and change it).

Django architecture is a bit different from classic MVC. Controller of the classic model MVC approximately corresponds the level, which is called “View” in Django. Presentation View logic is realized on the level of Templates. Due to this Django level architecture is frequently called “Model-Template-View” (MTV).

For models Django provides an abstraction level which frees from the necessity of writing SQL-requests for getting/saving data to the database. All the tables, that are used in the application, are written as classes in a separate file models.py. Then with the help of these classes methods there happens manipulation of the tables content in the code. Thus, work with database becomes fully object-oriented. Django supports work with the main databases (PostgreSQL, SQLite3, MySQL, Oracle).

Also, it is worth noting about a very flexible way of urls reflection on the application function – with the help of regular expressions.

While developing an application it is convenient to use built-in server. It automatically determines the changes in the files of the project source code and reboots. The result from changes made to the code immediately displays on a browser web-page, but it is not recommended to use it as a working one, as it is single-threaded and do not provide any security measures. For these purposes you will have to set a normal server (Apache, for example).

To be honest till the very end, I will enumerate Django disadvantages as well:

  • Though the template language is simple, still it is not very “pythonic”
  • Not very convenient work with AJAX
  • There can emerge some difficulties while replacing components (if you are in bad relations with regular expressions, which are used widely in urls reflection, you may want to use another dispatcher). It is widely believed that Django developers quite often invent bikes. Though Django allows doing this easily and quickly.

Although Django is one of the most popular Python frameworks, do not forget that framework is just an instrument; the choice should depend on the task set firstly, and only after that on its popularity.

Thank you for consideration. As usual, I would be happy to see your comments :)

Kind regards,

Nadya Klim

Nadya Klim
Nadya.Klim@altabel.com
Business Development Manager
Altabel Group – Professional Software Development

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